Apparatus for the automatic determination of a continuous bulk material throughput by means of a continuous balance

Abstract

An apparatus for the automatic determination of a continuous bulk material throughput through a continuous balance comprises a weighing vessel, an adjustable closure member for adjusting an outlet cross-section of the weighing vessel and an electronic weight difference measuring device. The closure member is connectable to the weighing vessel in the outlet region thereof which is formed as an adjustable wall part and is so arranged that when the closure member is in the open operating position, there is a free mass flow in the weighing vessel. Simultaneously it is ensured that the bulk material flows freely and unhindered from the outlet of the weighing vessel. In the process of the automatic determination of the bulk material throughput while using the apparatus either when maintaining a mass flow in the complete weighing vessel or with the mass flow stopped, a signal corresponding to the weight change in the weighing vessel per unit of time is derived and used for calculating the parameters of state of the bulk material flow.

We claim: 
     
       1. Apparatus for automatic control of throughput of a bulk material through a continuous balance, comprising: (a) a weighing vessel having an inlet opening and an outlet opening;   (b) weigh measuring means having an input and an output, said input being operatively connected with said weighing vessel;   (c) an adjustable closure member positioned in an outlet region of said weighing vessel and connected thereto for closing and opening the outlet opening of said weighing vessel, said closure member having means to movably position the closure member in said weighing vessel to define said outlet opening of said weighing vessel so as to adjust a shape and a size of said outlet opening to ensure in it's opened position a continuous mass flow of said bulk material within and out of said weighing vessel;   (d) position indicating means connected with said closure member and having an output;   (e) a dosing member positioned upstream of said weighing vessel and adapted for control by the continuous balance as a function of weight changes monitored by said weighing measuring means;   (f) control means having a program for controlling the throughput of bulk matearial, said control means having a first input, a second input, a first output, and a second output, said first input being operatively connected with said output of said weight measuring means, said second input being operatively connected with said output of said indicating means, said first output being operatively connected with said closure member to set a position of the closure member to meet a programmed product-dependent opening position with respect to a desired throughput, and said second output being operatively connected with a control input of said dosing member to adjust the position of the dosing member such that an output signal of the weight measuring means is kept within a given range by the program of said control means, the limits of said range being chosen to lie between a first and a second output signal value, the first value corresponding to the lowest filling level of the weighing vessel at which said continuous mass flow is still possible while the second value corresponds to the maximum filling level, thereby using the weighing vessel with a set shape and size of said outlet opening thereof to ensure desired throughput.   
     
     
       2. Apparatus according to claim 1, wherein the closure member comprises an adjustable movable wall part of said weighing vessel. 
     
     
       3. Apparatus according to claim 2, wherein said adjustable wall part is movable rectilinearly. 
     
     
       4. Apparatus according to claim 2, wherein said adjustable wall part is pivotally movable. 
     
     
       5. Apparatus according to claim 2, wherein the means movably position said closure member adjusts such at angles between 0° and 40° relative to a wall of said weighing vessel. 
     
     
       6. Apparatus according to claim 1, further including a supply line and a removal line, and wherein a portion of said supply line is positioned at a distance above said weighing vessel;   a portion of said removal line is positioned at a distance below said weighing vessel;   passage zones of said portion of said supply line, said portion of said removal line and said weighing vessel have essentially the same cross section; and   said portions of said supply and removal lines and said weighing vessel are aligned with each other to form a feed line.   
     
     
       7. Apparatus according to claim 1, wherein said weighing vessel rests on said weight measuring means which are electronic weight measuring means.